It isn't impossible Doug, just it is not
recommended per se (at least not by seahorse.org), but it really depends who you ask.
I still think you could do it as long as you are careful about what species you get. The main issue as far as I can gather is that higher temperatures make a ripe breeding ground for bacteria and thus the SH's are more susceptible to infection at a higher temp. Just be aware, have some medications on hand and a QT to use just in case.
Buy captive bred ponies if possible (Australia has several sources or you could try rayjay here on the board) that are found in a tropical climate as opposed to a temperate one. I'm going to ask for opinions over on the org and see what they say as their waiting period for new posters is rather annoying.
Ask Sphelps what his tank runs at. He has barbouri (I think?), which is one of the species less likely to suffer from issues with coral stings and of course his tank is gorgeous.